JP2009050990A - Precision roll lathe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce a burden on a cutting tool by eliminating the necessity of making a cutting edge of the cutting tool abut on a workpiece from the pushing direction at start of biting during processing etc. when the cutting tool and the workpiece are positioned before the processing. <P>SOLUTION: A saddle 26 is installed on a head so as to enable movement of the longitudinal direction (Z-axis) of a roll W, and a table 28 is installed on the saddle 26 so as to be movable to the direction (X-axis) orthogonal to the longitudinal direction of the roll W. A turning table 30 having a tool rest 32 mounted with the cutting tool 42 is provided on the table 28. A linear shaft (Y-axis) for moving the cutting tool 42 to the direction which is orthogonal to the longitudinal direction of the roll W and is a cutting direction of the cutting edge of the cutting tool 42 is provided on the tool rest 32. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a precision roll lathe, and more particularly to a precision roll lathe that is improved so that chipping does not occur in a diamond tool when the workpiece and the tool are aligned before machining.

  A machine tool for processing a roll includes a roll lathe. A roll lathe is a lathe in which a tool post equipped with a diamond tool is installed on a carriage. The basic usage is to process the circumferential groove while rotating the roll on the headstock and feeding the carriage back and forth (X axis). When machining the groove in the axial direction, the groove can be created in the axial direction by moving the carriage in the left-right direction (Z-axis) at high speed while indexing the roll on the headstock (C-axis).

  In recent years, with the advance of machine control technology, ultra-precision machining with a lathe has been realized. As a result, it has become possible to process a mold used for molding an optical lens even on a lathe. For example, the present applicant has proposed a vertical lathe for processing a mold for molding a Fresnel lens (Patent Document 1). This vertical lathe can process the V-shaped lens groove of the Fresnel lens molding die with high accuracy.

  Recently, it has been studied to form a lenticular lens sheet, a cross lenticular lens sheet, a prism sheet or the like used for a backlight of a liquid crystal panel by extrusion molding.

Therefore, the present applicant has proposed a precision roll lathe for processing a roll used for extrusion molding of these lens sheets (Patent Documents 2 to 6).
JP 2004-358624 A Japanese Patent Application No. 2006-130066 Japanese Patent Application No. 2006-135560 Japanese Patent Application No. 2006-156388 Japanese Patent Application No. 2006-165144 Japanese Patent Application No. 2006-166404

In ultra-precision machining with this type of lathe, the precision requirements for diamond tools used for the tool post of lathes are increasing. For this reason, it is an urgent task to establish a method for increasing the burden on the tool and preventing the tool from being worn or chipped.
In particular, in a roll lathe, as a preparation before machining, in order to grasp the relationship between a cutting tool and a workpiece, an operation of moving the tool post and applying the tip of the cutting tool to the workpiece is performed. At this time, it has been pointed out that chipping tends to occur at the cutting edge of the cutting tool. This is because of the following reasons.

  Actually, the shape of the workpiece before processing is not accurately known in advance. The surface of the workpiece is often coated with plating or the like. Furthermore, the core may not come out when the workpiece is attached to the machine. For this reason, in the case of a roll-shaped workpiece, the concentricity and roundness are not exactly determined, so at what position in the machining range the cutting depth is where the tip of the tool hits the workpiece. I don't know if I don't actually do it.

  Therefore, before machining, the tool post is moved once so that the cutting tool is brought into contact with the surface of the workpiece, and the position of the cutting tool at which the distance between the tip of the cutting tool and the workpiece becomes zero is investigated. When the position where the distance between the cutting edge of the tool and the workpiece becomes zero is determined, the entire surface of the workpiece is processed. Ultra-precision machining is performed after the entire surface has been processed.

  Conventionally, after a work is mounted on a machine, the direction in which the tool is moved to first contact the tool is a direction in which the work surface is struck toward the center of the work. Such a direction causes chipping at the cutting edge of the diamond tool. This is because, due to the nature of the crystal structure of diamond, the diamond bite is strong in the direction of scooping the workpiece, but not strong in the direction of thrusting. In particular, a diamond cutting tool used for ultra-precision machining has a sharp cutting edge, so that chipping is likely to occur due to impact when thrusting.

  In addition, in the ultra-precision processing of rolls, the range of fine processing is wide. For example, a range in which a roll having a length of 750 mm × a diameter of 310 mm is processed corresponds to a flat plate processing of 750 mm × 973 mm. For this reason, there is a problem that the load on the tool is heavy and wear is large.

  Therefore, the object of the present invention is to eliminate the problems of the prior art, eliminate the need for aligning the cutting tool and the workpiece by applying the cutting edge of the cutting tool to the workpiece before machining, An object of the present invention is to provide a precision roll lathe that reduces the burden, and eliminates chipping of the cutting edge particularly in the case of a diamond tool, and can guarantee ultraprecision machining with the diamond tool.

  Another object of the present invention is to provide a precision roll lathe capable of reducing the wear of a cutting tool so that roll processing with a wide fine processing range can be realized with high accuracy.

  In order to achieve the above object, the present invention provides a bed, a spindle base having a spindle installed on the bed and rotating the roll while holding one end of a roll as a workpiece with a chuck, and the spindle A tailstock arranged on the bed opposite to a table and rotatably supporting one end of the roll; and a saddle installed on the bed so as to be movable in the longitudinal direction (Z axis) of the roll; A table installed on the saddle so as to be movable in a direction perpendicular to the longitudinal direction of the roll (X-axis), and a swivel having a tool post installed on the table and attached with a cutting tool, The tool post is provided with a linear axis (Y axis) for moving the cutting tool in a direction perpendicular to the longitudinal direction of the roll and in the scooping direction of the cutting tool edge.

  Further, in the present invention, the tool post includes a tool post main body to which a plurality of tools are fixed, a tool moving mechanism that is attached to the tool post main body, moves the tool in a scooping direction, and constitutes the linear axis. It is characterized by having.

  In the present invention, the tool moving mechanism can be configured as a tool post attachment that is integrally attached to the tool post main body.

  In the present invention, the tool post attachment is a movable body having an attachment body attached to the tool post, a Y-axis servo motor, a position detector for detecting the position of the tool in the Y-axis direction, and a tool holder for holding the tool. And a ball screw mechanism that transmits the output of the servo motor to the bite holder can be configured as an integral unitized attachment.

  According to the present invention, it is not necessary to align the cutting tool and the workpiece by applying the cutting edge of the cutting tool to the workpiece before machining, thereby reducing the burden on the cutting tool, particularly in the case of a diamond cutting tool. , Chipping of the cutting edge can be eliminated, and ultra-precision machining with a diamond tool can be guaranteed.

  In addition, according to the present invention, each time a fine groove is machined on the roll, instead of applying the cutting edge of the cutting tool from the direction of striking the work, it can be inserted from the scooping direction, so the burden on the cutting edge of the cutting tool is reduced. In addition, it is possible to reduce the wear of the cutting tool so that roll processing with a wide fine processing range can be realized with high accuracy.

Hereinafter, an embodiment of a precision roll lathe according to the present invention will be described with reference to the accompanying drawings.
1 and 2, reference numeral 10 indicates a bed. On the bed 10, a spindle stock 12, a tailstock 14, and a carriage 16 are arranged. The workpiece is a roll-shaped roll W, and is rotatably supported by the headstock 12 and the tailstock 14.
The headstock 12 is disposed at one end of the bed 10 in the longitudinal direction. The headstock 12 includes a main body portion 17, a main shaft 18, a chuck 19 attached to the tip of the main shaft 18, and a servo motor 20 that drives the main shaft 18. The main shaft 18 is supported by a hydrostatic bearing (not shown) built in the main body portion 17. The chuck 19 grips the shaft of the roll W and transmits the rotation of the main shaft 18 to the roll W.

  In the head stock 12, the servo motor 20 that drives the main shaft 18 is configured as a built-in servo motor that directly drives the main shaft 18. The amount of rotation of the main shaft 18 is detected by the encoder 23. By feeding back the detection signal of the encoder 23 to perform position control and speed control of the spindle 18, the spindle base 12 has a function as an indexing axis (C axis) for indexing the roll W in the circumferential direction. A function for continuously rotating the main shaft 18 at a constant rotation speed (up to several hundred rotations) is added.

  Next, in FIGS. 1 and 2, the tailstock 14 is arranged on the bed 10 so as to face the headstock 12. A guide surface (not shown) is provided on the upper surface of the bed 10, and the tailstock 14 is movably installed. The tailstock 14 includes a main shaft 24 instead of a conventional general tailstock shaft, and a shaft of the roll W is rotatably supported by a chuck 25 attached to the main shaft 24. Such a tailstock 14 has the same basic configuration as the headstock 12 except that it does not have a servo motor.

Next, the carriage 16 will be described.
The carriage 16 includes a saddle 26 installed on the bed 10 so as to be movable in the axial direction of the roll W. A table 28 is installed on the saddle 26 so as to be movable in a direction perpendicular to the axial direction of the roll W.

  In the precision roll lathe according to this embodiment, the axis for feeding the saddle 26 is the Z axis, and the axis for feeding the table 28 on the saddle 26 is the X axis. In this precision roll lathe, in addition to the X axis and the Z axis, the spindle base 12 has a C axis, the cutter swivel base 30 provided on the table 28 has a B axis, and, as will be described in detail below, Is a machine tool with a total of 5-axis control.

  FIG. 3 shows the front of the blade swivel 30. A tool rest 32 is attached on the tool turntable 30. In this embodiment, the tool post 32 includes a tool post body 33 and a tool post attachment 34. The tool post attachment 34 can be attached to and detached from the tool post main body 33.

  Bits 31 are arranged on the tool post body 33 at predetermined intervals in the circumferential direction. In this embodiment, the number of cutting tools 31 is three, and the tool post 32 can be indexed by turning every 90 degrees. However, the number of cutting tools 31 is four and indexing is performed every 60 degrees. There are forms. A diamond tool is used for the tool post body 33 in the case of ultra-precision machining. The height position (core height) of the cutting tool 31 attached to the tool post body 33 can be manually adjusted by measuring on the machine.

  Next, the tool moving mechanism constituted by the tool post attachment 34 will be described. In FIG. 4, the tool post attachment 34 includes an attachment main body 35, a Y-axis servo motor 36, a linear scale 37, a movable block 38 movable in the Y-axis direction, that is, a vertical direction, a bite holder 39, and a ball. A screw mechanism 40 is included.

  The Y-axis servomotor 36 is connected to the ball screw 43 via the speed reducer 41. A ball nut 44 that is screwed into the ball screw 43 is fixed to the upper portion of the movable block 38. A bite holder 39 is fixed to the lower part of the movable block 38. A diamond tool 42 used for ultra-precision machining is attached to the tool holder 39. Reference numeral 45 denotes a guide for guiding the movement of the movable block 38.

  Such a tool post attachment 34 can be attached to the tool post main body 33 by tightening a bolt into the flange portion 35 a of the attachment main body 35. The tool moving mechanism constituted by such a tool post attachment 34 can move the diamond tool 42 attached to the tool holder 38 up and down, and the roll lathe of the present embodiment constitutes the Y axis. .

Next, the relationship between the X-axis, Y-axis, and Z-axis of the roll lathe and the moving direction of the diamond cutting tool 42 will be described.
In FIG. 3, the moving direction of the diamond cutting tool 42 by the Y-axis is cut so that the cutting edge of the diamond cutting tool 42 scoops the surface of the roll W with a rake angle in the rotating roll W. It is a direction (rake direction) parallel to the cutting direction. On the other hand, the direction in which the diamond cutting tool 42 moves by the X axis is a radial direction of the roll W, that is, a direction parallel to the direction in which the cutting edge of the diamond cutting tool 42 projects toward the center of the roll W. The direction of movement along the Z axis is the longitudinal direction of the roll W.

  In addition, when the tool post attachment 34 is removed, the tool 31 attached to the tool post main body 33 can be used for processing. In this case, the tool post main body 33 can turn around the turning axis B, so that the necessary cutting tool 31 can be determined. Further, in the tool post body 33, the height position (Y-axis direction) of the cutting edge of the cutting tool 31 can be adjusted by the thickness of the liner by placing a liner (not shown) under the cutting tool 31. It has become.

The precision roll lathe according to the present embodiment is configured as described above, and processing when the tool post attachment 34 is attached to the tool post main body 33 will be described.
Prior to machining, centering is performed when the roll W is attached to the headstock 12 and the tailstock 14, and then the positional relationship between the roll W and the diamond bit 42 of the tool post attachment 34 is as follows. Work to grasp.

  First, in FIG. 3, the tool post attachment 34 attached to the tool post main body 33 is indexed by the B axis so as to face the roll W. Then, the cutter swivel 30 together with the table 28 is sent along the X axis, and the diamond bit 42 is stopped at the position shown in FIG.

  At this position, the cutting edge of the diamond cutting tool 42 is at a position below the XZ plane including the center line of the roll W, and it is assumed that the cutting edge comes into contact with the roll W when moved upward along the Y axis. Is in position. It is assumed that the position of the diamond cutting tool 42 is known in advance by measurement on the machine.

  Next, in FIG. 4, in the tool post attachment 34, the diamond cutting tool 42 rises together with the movable block 38 driven by the Y-axis servomotor 36. In FIG. 5, if the cutting edge of the diamond cutting tool 42 contacts the surface of the roll W, the position on the X axis at this time indicates that the distance between the cutting edge of the diamond cutting tool 42 and the roll W is zero.

  As described above, according to the present embodiment, by attaching the tool post attachment 34 to the tool post main body 33, it is possible to add a linear axis Y axis that can move the diamond cutting tool 42 in the cutting direction.

  Thus, in the conventional alignment of the cutting tool and the workpiece before processing, it is not necessary to move the diamond cutting tool 42 in the striking direction, which is a direction weak against impact, due to the nature of the crystal structure of diamond.

  The direction of the Y axis coincides with the direction in which the cutting edge of the diamond cutting tool 42 scoops the surface of the roll W, and when the diamond 42 is contacted for the first time, the surface of the roll W is scooped. As a matter of course, the strength of the cutting edge of the diamond tool is extremely strong in this direction due to the nature of diamond. Therefore, even a diamond tool used for ultra-precision machining with a sharp edge (edge) does not cause chipping on the edge, and the diamond bit 42 and roll W can be aligned safely and accurately. It can be carried out.

  Thus, when the position on the X axis where the distance between the cutting edge of the diamond bit 42 and the roll W is 0 is known, the position on the X axis is fixed, and the diamond bit 42 is fed along the Z axis to process the roll W. The whole surface is processed. By this whole surface processing, the standard of processing is established. The ultra-precision main processing with the diamond cutting tool 42 is performed after that.

  In this ultra-precision main processing, for example, a fine groove is processed in the circumferential direction over the entire surface of the roll W. In this case, every time one minute groove is formed on the roll W, the cutting edge of the diamond cutting tool 42 can be inserted from the scooping direction using the Y axis instead of applying the cutting edge of the diamond cutting tool 42 to the roll W. The burden of is reduced. That is, when a fine groove is processed on the roll W, the processing range is widened, and the number of grooves is enormous because it is a fine groove. For this reason, every time the processing of one groove is completed and the next groove is processed, the diamond cutting tool 42 is inserted from the scooping direction using the Y-axis as described above, so that the load on the cutting edge of the diamond cutting tool 42 is reduced. It becomes lighter, and the effect of reducing the wear of the diamond tool 42 becomes remarkable in the entire main processing of one roll.

  In the precision roll lathe of this embodiment, even if the tool post attachment 34 is removed from the tool post body 33, the roll can be processed by the tool 31 of the tool post main body 33 in accordance with the usage of a normal roll lathe. Of course.

  As described above, the precision roll lathe according to the present invention has been described with reference to the embodiment in which the Y axis is added by attaching the tool post attachment, but the present invention is not limited to this embodiment, and from the beginning. The Y axis may be fixedly configured.

It is a side view which shows the precision roll lathe by one Embodiment of this invention. It is a top view of the precision roll lathe. The side view which shows the state by which the tool post attachment was attached to the tool post of the precision roll lathe by one Embodiment of this invention. The side view which shows a tool post attachment. The side view which shows the state which the bite moved with the tool post attachment, and contacted the roll.

Explanation of symbols

10 Bed 12 Spindle base 14 Tailstock 16 Reciprocating base 26 Saddle 28 Table 30 Tool turntable 31 Tool 32 Tool post 33 Tool post body 34 Tool post attachment 36 Y-axis servo motor 38 Movable block 39 Tool holder 40 Ball screw mechanism 42 Diamond Byte W Roll

Claims (5)

Bed and
A headstock having a spindle installed on the bed and providing rotation to the roll while holding one end of the roll as a workpiece;
A tailstock arranged on the bed facing the headstock and rotatably supporting one end of the roll;
A saddle installed on the bed movably in the longitudinal direction (Z-axis) of the roll;
A table installed on the saddle so as to be movable in a direction (X axis) perpendicular to the longitudinal direction of the roll;
A swivel with a tool post mounted on the table and having a cutting tool attached thereto,
A precision roll lathe, wherein the tool post includes a linear axis (Y axis) for moving the cutting tool in a direction perpendicular to the longitudinal direction of the roll and in the scooping direction of the cutting tool edge.   The turret has a turret body to which a plurality of cutting tools are fixed, and a cutting tool moving mechanism that is attached to the turret body and moves the cutting tool in a scooping direction to constitute the linear axis (Y axis). The precision roll lathe according to claim 1.   The precision roll lathe according to claim 2, wherein the tool moving mechanism is configured as a tool post attachment that is integrally attached to the tool post body.   The tool post attachment includes an attachment main body attached to the tool post, a Y-axis servo motor, a position detector for detecting the position of the tool in the Y-axis direction, a movable body having a tool holder for holding the tool, and a servo motor. The precision roll lathe according to claim 3, wherein the ball screw mechanism that transmits the output of the tool to the tool holder is an attachment unitized as a unit.   The precision roll lathe according to claim 4, wherein the tool attached to the tool post attachment is a diamond tool.

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